Convert OBJ to X (DirectX) Online — Legacy Game Engine Format
Convert OBJ files to X (DirectX) format for use in legacy DirectX game engines, modding tools, and visualization applications from the DirectX 7-9 era. The X format was Microsoft's native 3D model format before FBX became the industry standard.
Last updated Mar 2026
Drag OBJ file here (with MTL & textures), or upload a ZIP
Supports .obj files (+ .mtl, textures, or .zip) up to 150MB
Usually under 3 seconds — depends on file size.
What You Should Know
What Changes During Conversion
Geometry (vertices, faces, normals) is preserved. UV coordinates are maintained. Materials are converted from OBJ's MTL format to X's material templates (basic diffuse/specular). Polygon faces are triangulated if needed — the X format works best with triangle meshes. Object groups from OBJ become Frame nodes in the X hierarchy.
X Format Characteristics
The DirectX X format supports geometry, materials, UV mapping, and skeletal animation. It uses a template-based structure that can be text (human-readable) or binary. The format was introduced with DirectX 2 and was the primary 3D format through DirectX 9. While largely replaced by FBX and glTF in modern pipelines, it remains essential for legacy DirectX applications.
OBJ vs X (DirectX): Quick Comparison
| Feature | OBJ | X (DirectX) |
|---|---|---|
| Geometry | Polygons + triangles | Triangles preferred |
| Materials | MTL files (basic) | Inline templates (basic) |
| Animation | Not supported | Skeletal animation supported |
| UV Mapping | Supported | Supported |
| Primary Era | Universal (1990s–present) | DirectX 7-9 (late 1990s–2000s) |
| File Type | Text only | Text or binary |
Use OBJ for universal compatibility across all 3D tools. Convert to X only when targeting legacy DirectX engines, game modding tools, or educational DirectX projects that require .x format.
When to Convert OBJ to X (DirectX)
Legacy DirectX Game Development
Load models into DirectX 7-9 era game engines and frameworks. Many educational DirectX tutorials and older game engines (including custom engines built on D3DX) require .x format input for mesh loading via D3DXLoadMeshFromX.
Game Modding
Create mods for older DirectX-based games that accept .x model files. Many classic PC games from the early 2000s use the X format for custom assets, vehicles, weapons, and map objects.
DirectX Programming Education
Many DirectX programming textbooks and courses use .x files for examples. Convert freely available OBJ models to X format for use in DirectX learning projects and shader development.